We have studied the magnetoresistance ͑MR͒ of compressively strained La 0.7 Sr 0.3 MnO 3 ͑LSMO͒ films in various magnetic states in order to understand the role of magnetic domain structure on magnetotransport. In thin films of LSMO on ͑100͒ LaAlO 3 , the perpendicular magnetic anisotropy results in perpendicularly magnetized domains with fine scale ϳ200 nm domain subdivision, which we image directly at room temperature using magnetic force microscopy. The main MR effects can be understood in terms of bulk colossal MR and anisotropic MR. We also find evidence for a small domain wall contribution to the MR, which is an order of magnitude larger than expected from a double exchange model.The doped perovskite manganites have received an enormous amount of attention recently because they exhibit colossal magnetoresistance ͑CMR͒ and may be half metallic, with complete spin polarization at the Fermi level. For these reasons, they may find important uses in magnetoresistive devices, such as magnetic random access memory and sensors. As has been found in magnetoresistive devices based on transition metal ferromagnets, controlling the electronic transport and magnetic properties of these materials in thin film form will be essential to applications. Experimentally, the magnetic and transport properties of colossal magnetoresistance materials have been shown to be highly sensitive to microstructure as well as lattice distortions both in thin film and bulk form. Many groups have shown that properties such as Curie temperature, resistivity and magnetoresistance effect are extremely sensitive to chemical and hydrostatic pressure as well as lattice mismatch with an underlying substrate.1-11 Studies of bulk polycrystalline pellets, thin films of varying polycrystallinity and isolated grain boundaries have shown that the magnetoresistance is profoundly affected by transport across grain boundaries. 2,12,13 Magnetic domain structure may also to lead to distinctive magnetotransport effects in thin films. Mathur et al. report that the measured resistivity of a magnetic domain wall is four orders of magnitude larger than that predicted by a simple double exchange picture.14 Wang et al. have also suggested that large low field magnetoresistance ͑MR͒, in ultrathin compressively strained doped manganite thin films, may be due to domain wall scattering.9 In order to address these questions in LSMO, we have prepared in-plane compressively strained films of LSMO on ͑001͒ LAO (aϭbϭc ϭ3.79 Å) substrates using pulsed laser deposition.9 These films naturally split into stripe domains with length scales set by the strain and film thickness. This enables us to study the effect of magnetic microstructure on MR in a systematic manner. In this letter, we have investigated the magnetics and magnetotransport of epitaxial La 0.7 Sr 0.3 MnO 3 ͑LSMO͒ films. The main MR effects can be explained by CMR and anisotropic MR. We also find evidence for a small domain wall ͑DW͒ contribution to the MR, which is an order of magnitude larger than expected based ...

Mainland Chinese adolescents have specific depressive symptom structure, which is consistent across gender.

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Technologies bring a new era of content presentation for online teaching and learning. With more instructors adopting new tools to design online teaching materials, students are often put into learning contexts with certain new design components. Assessing learner experience and outcome in these contexts is challenging because of the complexity involved, as social and individual factors and behavioural impacts of using the new components have to be considered. Few studies have been reported in the literature identifying behavioural factors of learners' online learning experience when they interact with the content. Factors that affect learners' online learning experience, especially the affect factors, are less understood. This study therefore proposed and tested a model that explains the relationships among the affect factors and outcome behaviours of participants' online learning experience, taking into account individual difference, and employing a comparison based on a difference in content presentation. The data were collected from a professional training course offered by a university in the United States. The results support the assumption that time spent in study affects learning outcome and other outcome related behaviours. Also, positive relations between perceived quality of content design and outcome behaviour were found, indicating the effects of sense of presence and feeling of enjoyment on performance of creative tasks. The study intends to foster a deeper understanding of motivation and behaviours of online learning under innovative content design.